Angular die set for changing the direction of the tool pressure stroke in a punch press



March 31, 1970 F. J. THOMAS 3,503,630

ANGULAR DIE SET FOR CHANGING THE DIRECTION OF THE TOOL PRESSURE STROKE IN A PUNCH PRESS Filed Aug. 1, 1966 2 Sheets-Sheet 1 INVENTOR. FRANK J. THOMAS BY McNENNY, FARRINGTON,PEARNE BGORDON ATTORNEYS March 31, 1970 F. J. THOMAS 3,

LNGULAR DIE SET FOR CHANGING THE DIRECTION OF THE TOOL PRESSURE STROKE IN A PUNCH PRESS Filed Aug. 1, 1966 2 Sheets-Sheet 2.

INVENTOR. FRANK J. THOMAS BY McNENNY,FARRINGTON,PEARNE a sonoou ATTORNEYS United States Patent US. Cl. 72324 23 Claims ABSTRACT OF THE DISCLOSURE Disclosed is a cam set comprising a first heel block element having a planar cam surface and adapted to be secured to a base plate, a second tool carrying element having a planar cam surface inclined with respect to said cam surface of said first element, the second element is also adapted to be secured to the base plate. A third floating V-block element has a first and second planar cam surfaces inclined with respect to each other, and the first and second planar cam surfaces of the third element mate with the cam surfaces of said first and second elements by a tongue and groove couple so that they interlock. The third floating element is provided with a drive pin whereby a driving post may engage said floating element and cause it to move in a direction parallel to the planar surface of one of the two other elements when said one element is held stationary with respect to said third element and the other of said two other elements so that the other element which is tool carrying moves an amount equal to the accumulated displacement of both sides of the third V-block element. The driving post is connected to another base plate which in a punch press reciprocates relative to the first base plate on which the heel block is mounted. Also disclosed are tools and dies for a typical punch press operation illustrating uses of the invention.

This invention relates to improvements in tool actuating mechanisms for use in punch presses or the like and more particularly relates to an angular die set for changing the direction of travel of tools and the tool pressure stroke of trimming dies, flanging dies, piercing and perforating dies and the like.

The typical die set comprises a pair of die supporting parallel plates between the ram and bed of a punch press which are maintained in relative alignment by a plurality of leader pins secured to one of the plates and slidable in openings in the other plates. My invention will be found in the illustrated die set which is located between these two plates and which, besides aiding in maintaining the plates in relative alignment, is particularly useful in changing the direction of forces applied by the ram an amount of 90 degrees or more so that a number of operations can be performed at the same press stroke. The advantage in time saved and consequent economies of operation is evident. The employment of the present invention will enable this result to be achieved under satisfactory performance conditions which have conventionally required the operation of hydraulic or pneumatic cylinders or an additional press operation.

It is an important object of my invention to provide a tool-actuating mechanism of the V-block cam-die type, whereby the tool is driven positively in alternate directions the same distance at an angle inclined relative to the ram as the ram advances and retracts.

It is another object of my invention to provide means for increasing the horizontal stroke distance of the tool to an amount greater than three-quarters of the vertical ram stroke, the conventional limit in practice today.

Another important object of the present invention is 3,503,630 Patented Mar. 31, 1970 the elimination of separate returns such as air pins, springs and lever returns for the tool holder while providing a first cam member actuator associated with a second cam member with co-acting tongue and groove elements provided on the member to insure their retention in proper relationship with one another while also permitting movement of one cam with respect to the other.

It is another important object of my invention to pro- Vide the V-block actuator or drive cam of a punch press with T-shaped tongue and groove elements which co-act with the heel block and sliding tool block to guide and move the tool block in a direction inclined relative to the direction of movement of the ram.

A fuller and more complete understanding of my invention will be had by referring to the following description of my preferred embodiment with reference to the drawings, and to the appended claims.

In the drawings:

FIGURE 1 is a schematic view of a die set up showing my preferred embodiment as actually working a piece, the position of the various elements being slightly exaggerated for a more complete understanding of the structure of the illustrated embodiment.

FIGURE 2 is a schematic plan view of a set up employing an embossing tool on another workpiece.

FIGURE 3 is a sectional view of the T-shaped mating tongue and groove elements of the drive cam and slide block of FIGURE 2 taken along line 33.

FIGURE 4 is a perspective view of the die set shown at the right of the work piece of FIGURE 1.

FIGURE 5 is a schematic diagram of a die set incorporating the present invention to obtain a greater travel of the tool holder in the horizontal direction than may be obtained using a single V-block actuator.

As stated previously the press ram (not shown) and bed (not shown) are each provided with a plate between which the illustrated die set is placed. Leader pins which are not shown in the drawing slide in one of the plates to keep the plates in alignment so that the dies which are secured to the plates are themselves properly aligned.

As shown in the drawings the upper die shoe or ram plate 11 and the lower die shoe or bolster plate 12 are secured to the press above and below the work piece 14 respectively. The work piece is placed upon a die forming support 13 and as the ram travels downward the spring biased pressure pad 16 contacts the work piece and holds it in position until the ram bottoms out, finally forming the piece. For light gage sheet such as is shown being worked in FIGURE 1, the springs 21 exert suflicient pressure to form the work piece to the point where it may be acted upon by the tools carried on sliding tool blocks 22 and 26.

It will be understood that the bolster 12 is generally fastened to the bed of the press while the ram plate is suitably secured to the ram, so that in FIGURE 1, ram plate 11 will be understood to reciprocate toward and away from the bolster 12.

The pressure pad 16 guided by suitable pins (not shown) traveling with the ram plate 11 and spring biased away from it contacts the work piece 14 and forms it so that it is preformed to the point where the forward movement of the trimming tool 57 can trim the flash and the flanging plate 157 can bend the work piece to form a flange between the pressure pad 16 and the forming support 13 as shown in FIGURE 1.

Since it is often desirable I have provided that the drive posts 17 and 117 can automatically engage the first members 18 and 23 of the die set which move in a direction inclined to the ram stroke and which automatically disengage these members, V-block cam 18 and V-block cam 23.

As the ram travels forward and downward the driver posts 17 and 117 secured to the upper die shoe 11 forces the actuating V-block earns 18 and 23 in the same first direction. The action of the cam 18 on the heel block 19 changes the direction of the applied force to move the sliding tool blocks in the desired direction. This is usually, as in FIGURE 1, either at right angles to the direction of applied force as at 26 or at an angle exceeding 90 degrees at 22. The V-block cams 18 and 23 when driven against the stationary heel block 19 and 24, moves laterally against the tool blocks carrying them in a similar direction laterally toward the workpiece. The shape of the wedge may vary depending upon the direction and distance that the tool block is to be carried or the force required for the operation.

Neglecting friction with 45 degree cams the side thrust equals the vertical force of the cam driver. Because of friction, however, it is common practice to limit the V-block cam wedge to an angle less than this As the angle of the actuating cam decreases there is a corresponding decrease in horizontal or lateral travel of the tool block. At the present time angular cams are not usually employed in an operation where their incorporation for actuation by the stroke of the ram would require the tool block to move a distance greater than three-quarters of the vertical stroke of the ram. Where they are employed they require hydraulic or pneumatic actuators. In most cases a second operation is used.

When the present invention is employed I have found that it is practical to machine the wedge so that the included angle may equal 80 degrees. If, as at the vertically traveling actuating V-block cam 23, the nose of the V-block has an included angle A of 60 degrees then the action of the cam 23 on the stationary heel block 24 will cause punch holder 26 to travel horizontally a distance equal to two times the quantity, tangent the included angle A times the vertical stroke of the ram, a distance greater than the ram stroke.

Control of the cams and the tool holders is achieved by mating tongue and groove elements. The position of the cams 18 and 23 is controlled as seen in FIG. 3 by mating a T-slot race 29 on the angular cam surface of the heel block 19 with a T-rail or projection 31 on the cam. Horizontal or transverse motion of the actuating cam 18 is permitted by the co-action of the projection, pin 28, which is T-shaped in cross section and threadedly secured to the upper surface of the actuating cam 18 and a T-slot race provided in the driver post 17. This structure permits the increase in horizontal travel previously mentioned while positively assuring the precise control of the position of the actuating cam 18 and constrains it to one degree of freedom reciprocating in the direction determined by the heel block.

The pin may be machined from the same stock as the V-block cam 18. In any case, the T-projection 28 and 128 adapted to slidably engage the T-slot race in the driver post as the ram plate and driver posts near the bottom forward position, at which point the projection comes in contact with the lower surface of the drive post 17 and 117, thus forcing the V-block cams 18 and 23 respectively against the inclined cam surface of the heel block 19 and 24. The horizontal component of this thrust on the V-blook causes the pin or T-bolt to engage and mate with the corresponding T-slot race 25- and 125 of the driver posts 17 and 117 respectively, locking the cams 18- and 23 to the post 17 and 117 in a sliding fit. When the ram retracts, the pin is disengaged from the driver post by forces acting on the elements in an opposite direction. Thus, this dies set is adapted for use in presses where the stroke of the ram is greater than would be possible of the projections 28 and 128 could not leave the races 25 and 125 A ball nosed spring biased holding pin 35 is provided in the heel block to hold the actuating V-block cam 18 in its upward position after the pin 28 has disengaged the driver post 17 on the return stroke of the ram. The holding pin 35 assures the proper position of the V-block for the next forward stroke of the ram.

Another important advantage achieved by my invention is the positive control of the position of the sliding tool block 22 and 26. The tool blocks are mated with the actuating V-block cam 18 or 23 in a manner similar to that just described between the actuating cams and the heel blocks. Such a mating tongue and groove arrangement according to my preferred embodiment is illustrated by the view shown in FIGURES 3 or 4.

Preferably the tool holders are limited to reciprocable movement relative to the bolster by a gib 55 or and key 56 or 156 structure as seen in FIGURE 1. If the tool holder is to travel horizontally, it would be constrained by securing it directly to the bolster 12 as gib 155 is secured directly to the bolster 12- by suitable fastening means. On the other hand a guiding surface may be an inclined cam element 50 which acts to carry the tool holder 22 upward. Thus gib 55' is secured to element 50.

A T-rail projection as shown at 31 in FIG. 4- is preferred where there may be torque applied to the V-block actuating cam 26 so that the torque is carried to the bolster. Furthermore this arrangement is most desirable where a plurality of V-blocks are used, such as the arrangement shown in FIGURE 5.

In the arrangement illustrated in FIGURE 5, a plurality of V-blocks are employed to move the tool holder 36 horizontally. It will be appreciated that FIGURE 5 is a schematic representation not showing the T-slot and mating T-bolts which are employed on each camming surface as previously illustarted and described with reference to FIGURES 2 and 3. When a plurality of actuating cams are utilized if the first 37 and second 38 cams are the same angles off the vertical, the horizontal travel of the tool holder 36 will be approximately twice the horizontal travel when one cam is employed. In such an arrangement, however, it is necessary to employ a traveling heel block 39 as well as the stationary heel block 41. Preferably, the traveling heel block is fastened to the bolster 42 by means of a gib 43 fastened by suitable means such as bolts 44 to the bolster 42 which provide a race for keys on the traveling heel block 39 and the tool holder 36.

The operation of the arrangement shown in FIGURE 5 is as follows. As the ram forces the ram plate 46 downward the two driving posts 47 and 48 meet and mate with the T-blocks 49' and '51 at synchronous moments thus actuating the blocks '52 and 53 downwardly. The action of the V-block 52 on the stationary heel block 41 forces the traveling heel block 39 to the left. Simultaneously, the co-action of the cam surface of the V-block 52 and the traveling heel block 39 actuate the tool holder 36 in the direct indicated. The synchronous return of the actuating cam V-blocks 52 and 53 pulls the tool holder and traveling heel block to the right in the direction indicated by the arrows. In such an arrangement the lock pins are situated preferably in the stationary heel block and the traveling tool holder.

In those cases where it is desirable to mount the tool holder on the ram plate the embodiment shown in FIG- URE 2 may be employed. In the figure ram plate 211 carries tool holder 222 which is secured to it by a gib 255 and mating key 256 (in phantom) so that the tool holder carrying an embossing tool 240 will reciprocate horizontally to emboss the end of workpiece 214. In embodiment the support 213 is fixed on ram plate 221 while the spring biased pressure pad is carried on bolster 212. The bolster 212 also has fixed to it the drive post 217. Therefore when drive post 217 engages the V-block earn 218 it thrusts the V-block in a vertical direction. The heel block 219 turns this thrust so that the resultant thrust on the tool holder 222 is in the horizontal direction.

In this embodiment, as shown by the sectional view taken along line 33 of FIGURE 2, a T-rail 231 slides in a T-slot race 232 so that the V-block cam 218 reciprocates in one predetermined direction on a mating cam surface such as the mating cam surface on the tool holder 222.

While the preferred embodiment and various arrangements of the angular die set for changing the direction of travel of tools in a punch press have been shown and described in considerable detail, it is to be understood that this invention is not limited to the particular forms described and shown nor to a slavish imitation thereof, but various modifications and rearrangements may be made without departing from the scope of the invention as set forth and defined in the following claims.

What is claimed is:

1. An angular die set for changing the direction of the tool pressure stroke in a press having first and second plates at least one of which reciprocates toward and away from each other in a first direction, comprising first and second cam members formed with interlocking mating camming surfaces permitting relative reciprocation therebetween only in a second direction inclined relative to said first direction, said first cam member being adapted to be secured to a first one of said plates, said second cam member being formed with means adapted to connect with the other of said plates and to limit relative movement therebetween to reciprocation in a third direction inclined to both said first and a second directions at least during a predetermined portion of the movement between said plates.

2. An angular die set according to claim 1 wherein said means are adapted to provide automatic disengagement between driving means of said other plate and second cam member when said plates are in a second predetermined portion of their relative movement.

3. An angular die set according to claim 2 wherein the mating means of said mating camming surfaces include a T-slot on one of said cam members and a T-projection on the other camming member, and said means include a T-slot and T-projection proportioned so that the T-projection moves axially out of its T-slot when said other plate moves to said second predetermined portion of their relative movement.

4. An angular die set according to claim 2 wherein a third cam member is provided having planar camming surfaces mating with said second cam member permitting relative movement therebetween only in a fourth direction being inclined relative to said second direction, said third cam member being formed with means adapted to connect with said first plate and to limit relative movement therebetween to a fifth direction inclined relative to the fourth direction.

'5. An angular die set according to claim 4 wherein said fifth direction is at an angle inclined more than 90 degrees from said first direction.

6. An angular die set according to claim 4 wherein holding means are provided to hold said second cam member in the relative position it has at disengagement of said members until the next point of engagement in the reciprocation cycle.

7. An angular die set for changing the tool pressure stroke in a press to an angle inclined 90 degrees or more from a first direction, comprising first and second plates reciprocable toward and away from one another, first and second driving cam elements in a fixed position relative to and being on one of said plates, and first and second cam follower members mating with said first and said second driving cam elements respectively for reciprocating movement, said first and said second cam follower members mating with each other for relative reciprocating movement, a said first cam follower member likewise being connected to the other of said plates such that relative movement therebetween is restricted to reciprocating movement, said second cam follower member mating with a third cam follower member and said third follower member being constrained to movement in a second direction relative to said other of said plates such that said third follower member reciprocates at an angle degrees or more from said first direction.

8. An angular die set according to claim 6 wherein each adjacent cam surfaces is connected to the other by T-slot and 'T-projection;

9. An angular die set according to claim 7 wherein one of said first driving cam elements has a camming surface adapted to engage a locking key member on its respective cam follower and to cause said key member to enter a race provided in said first driving element when the ram of the press is at the forward end of its reciprocating stroke and to disengage said key from said race when said ram is at the rearward extreme of its stroke such that said driving element and its respective cam follower are constrained to relative sliding movement in a direction inclined to said first direction.

10. An angular die set for changing the direction of the tool pressure stroke in a punch press, comprising an upper ram plate and a lower bed plate, a stationary heel block secured to one of said plates, a driving post for a V-block cam actuator member, a cam follower member engaging and ararnged to be driven by said V-block at an angle inclined relative to the stroke of the ram of the punch press, a connecting key on said V-block adapted to engage and a slide in a groove on the adjacent surface of the driving post when the ram is in the forward portion of its stroke and to become disengaged from said post when the ram retracts to its rearward position. said V-block and said heel block being connected by a T-slot and mating T-projection, said V-block and said cam follower likewise being provided with a T-slot and T-projection connection to insure proper engagement at all times and to insure reciprocation of the cam follower element being keyed to an inclined surface on said one of said plates so that said cam follower may turn the direction of the pressure stroke an angle exceeding 90 degrees, and means to retain said V-block in its position at that point in its reciprocating stroke when said key disengages said driving post while said V-block and driving post are disengaged.

11. A cam set comprsing a first element having a planar cam surface and adapted to be secured to a base plate, a second element having a planar cam surface inclined with respect to said cam surface of said first element, said second element being adapted to be secured to said base plate, a third floating element having a first and second planar cam surfaces inclined with respect to each other, said first and second planar cam surfaces of said floating element mating with the cam surfaces of said first and second elements, said third floating element being provided with means whereby driving means may engage said floating element and cause it to move in a direction parallel to the planar surface of one of the two other elements when said one element is held stationary with respect to said third element and the other of said two other elements whereby said floating element floats relative to said driving means in a direction normal to the direction of driving force.

12. A cam set comprising a first element having a planar cam surface and adapted to be secured to a base plate, a second element having a planar cam surface inclined with respect to said cam surface of said first element, said second element being adapted to be secured to said base plate, a third floating element having first and second planar cam surfaces inclined with respect to each other, said first and second planar cam surfaces of said floating element engaging the cam surfaces of said first and second elements, said third floating element being provided with means whereby driving means may engage said floating element and cause it to move in a direction parallel to the planar surface of one of the two other elements when said one element is held stationary with respect to said third element and the other of said two other elements whereby said floating element floats relative to said driving means in a direction divergent of the direction of driving force and said floating element causes the said other of said two other elements to have a cumulative movement determined by the angular relationship of said first and second planar cam surfaces of said floating element.

13. A cam set according to claim 12 wherein said set is adapted for changing the direction of the tool pressure stroke in a press having first and second plates at least one of which reciprocates toward and away from each other in a first direction and wherein said first and second elements are secured to the first of said plates, and said third element is adapted to be driven by the second of said plates.

14. A cam set according to claim 12 wherein said third element is provided with means to permit automatic disengagement between said driving means and said third element at a predetermined point in the relative movement between said third element and said driving means.

15. A cam set according to claim 12 wherein the means for the mating of said elements at said ca-m surfaces is provided by a key projecting from one cam surface of one element interconnecting a corresponding slot in the corresponding mating cam surface of another element.

16. A cam set according to claim 12 wherein said means provided for said third element whereby said driving means may engage said third element comprising key and slot interconnecting means.

17. A cam set according to claim 12 wherein constraining means are provided to engage said second element and constraining the movement of said second element to movement obliquely to the direction of movement of said driving means.

18. A cam set according to claim 14 wherein holding means are provided to hold said third element in the relative position it has at disengagement of said third element from said driving means until a subsequent engagement by said driving means.

19. A cam set according to claim 12 wherein a fourth element is provided and has a cam surface mated with a cam surface of said second element such that said second element during movement of said third element causes movement of said fourth element.

20. A cam set according to claim 19 wherein said fourth element is a floating element adapted to engage said driving means and float in a direction divergent from the direction of movement of said driving means.

21. A cam set according to claim 20 wherein a fifth element is connected to said'fourth element and moved thereby.

22. A cam set according to claim 12 wherein said first and second planar cam surfaces of said floating element mate with mating cam surfaces of said first and second elements and said floating element floats relative to said driving means in a direction normal to the direction of driving force.

23. A cam set according to claim 12 wherein said cumulative movement is greater when said one element is held stationary than when it is not held stationary.

References Cited UNITED STATES PATENTS 180,169 7/1876 Tasker 72393 1,671,619 5/1928 Vance 83133 2,539,085 1/1951 Kerseg 83-627 1,912,930 6/1933 Brett 72.---452 2,433,040 12/ 1947 Geist 72-4-52 2,554,916 5/1951 Miller 72-452 FOREIGN PATENTS 1,034,436 6/1966 Great Britain.

OTHER REFERENCES Die Design Handbook," 2nd edition, McGraw-Hill, 1965, pp. 3-27, 354, 5-9, 9-9.

CHARLES W. LANI-LAM, Primary Examiner E. M. COMBS, Assistant Examiner 

